package io.renren.util;

import org.springframework.beans.BeansException;
import org.springframework.beans.factory.NoSuchBeanDefinitionException;
import org.springframework.beans.factory.config.BeanFactoryPostProcessor;
import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
import org.springframework.beans.factory.support.DefaultListableBeanFactory;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.context.ConfigurableApplicationContext;
import org.springframework.stereotype.Component;
import org.springframework.util.Assert;

/**
 * @author wzzhenglong@qq.com
 */
@Component
public final class SpringUtils implements ApplicationContextAware, BeanFactoryPostProcessor {

  private static ApplicationContext applicationContext;

  /**
   * Spring应用上下文环境
   */
  private static ConfigurableListableBeanFactory beanFactory;

  @Override
  public void postProcessBeanFactory(ConfigurableListableBeanFactory beanFactory) throws BeansException {
    SpringUtils.beanFactory = beanFactory;
  }

  @Override
  public void setApplicationContext(ApplicationContext applicationContext)
          throws BeansException {
    SpringUtils.applicationContext = applicationContext;
  }

  public static ApplicationContext getApplicationContext() {
    return SpringUtils.applicationContext;
  }

  public void destroy() {
    applicationContext = null;
  }

  public static Object getBean(String name) {
    Assert.hasText(name, "bean名称不能为空!");
    return beanFactory.getBean(name);
  }

  /**
   * 获取类型为requiredType的对象
   *
   * @param clz
   * @return
   * @throws BeansException
   */
  public static <T> T getBean(Class<T> clz) throws BeansException {
    T result = (T) beanFactory.getBean(clz);
    return result;
  }

  @SuppressWarnings({"unchecked", "rawtypes"})
  public static Object getBean(String name, Class type) {
    Assert.hasText(name);
    Assert.notNull(type);
    return beanFactory.getBean(name, type);
  }

  /**
   * 如果BeanFactory包含一个与所给名称匹配的bean定义，则返回true
   *
   * @param name
   * @return boolean
   */
  public static boolean containsBean(String name) {
    return beanFactory.containsBean(name);
  }

  /**
   * 判断以给定名字注册的bean定义是一个singleton还是一个prototype。 如果与给定名字相应的bean定义没有被找到，将会抛出一个异常（NoSuchBeanDefinitionException）
   *
   * @param name
   * @return boolean
   * @throws NoSuchBeanDefinitionException
   */
  public static boolean isSingleton(String name) throws NoSuchBeanDefinitionException {
    return beanFactory.isSingleton(name);
  }

  /**
   * @param name
   * @return Class 注册对象的类型
   * @throws NoSuchBeanDefinitionException
   */
  public static Class<?> getType(String name) throws NoSuchBeanDefinitionException {
    return beanFactory.getType(name);
  }

  /**
   * 如果给定的bean名字在bean定义中有别名，则返回这些别名
   *
   * @param name
   * @return
   * @throws NoSuchBeanDefinitionException
   */
  public static String[] getAliases(String name) throws NoSuchBeanDefinitionException {
    return beanFactory.getAliases(name);
  }


  public static DefaultListableBeanFactory getDefaultListableBeanFactory() {
    return (DefaultListableBeanFactory) ((ConfigurableApplicationContext) applicationContext).getBeanFactory();
  }
}
